Many machines have been developed for excavating. One commercially available type of machine often used for excavating, for example in a trenching operation, is a backhoe. Generally, a backhoe is mounted on a tractor or other machine body moveable along the ground on wheels or tracks. The backhoe may be the only excavating assemblage or handling implement on the tractor or machine body, or it may be one of a plurality of implements. For example, one relatively common machine, generally known as a backhoe loader, may include a backhoe mounted at one end of a tractor, and may include a loader bucket and accompanying operating linkage mounted at the other end of the tractor.
A typical backhoe may include a boom, a stick, and a bucket. In general, the boom may be pivoted to the machine for movement in a generally vertical plane, the stick may be pivotally mounted to the boom for movement in the same generally vertical plane, and the bucket may be pivotally mounted to the stick. The stick may be a fixed length element or it may be of the extendable, e-stick type. Each of the boom, stick, and bucket may be moved about a pivotal connection by one or more actuators, such as hydraulic cylinders. The entire excavating assemblage of boom, stick, and bucket may be mounted on the machine body for swinging movement in a generally horizontal plane relative to the machine body.
Another relatively common machine that employs a backhoe-type implement is generally known as a hydraulic excavator. A hydraulic excavator may have a number of features in common with the backhoe of a backhoe loader. For example, a hydraulic excavator may include a boom, a stick, and a bucket as the excavating assemblage. However, in a hydraulic excavator, the excavating assemblage does not swing in a horizontal plane relative to the machine body as does the excavating assemblage in a backhoe loader. Rather, in a hydraulic excavator, the entire upper machine body rotates relative to an undercarriage. Thus, the position of the excavating assemblage on a worksite in a relatively horizontal plane is altered by rotating the entire upper machine body.
In excavating a trench, for example, the operator of a machine, such as a backhoe, manipulates the machine controls to cause the boom, stick, and bucket to move in coordination such that the bucket digs into the earth generally along the direction of extent of the proposed trench. The bucket is moved about its pivot to become filled with earth, the filled bucket is held in a curled position relative to the stick, and lifted by coordinated movement of the boom and stick from the trench being formed. The excavating assemblage of boom, stick, and bucket is then swung away from the trench for dumping, either into a pile adjacent the trench, or into a waiting container or carrier, such as a dump truck.
A proposed excavation may be larger in extent than the reach from a single set-up location of the machine that is selected to create the excavation. For example, where a backhoe loader is selected to excavate a trench of some defined length, the backhoe loader may only be capable of excavating a portion of the trench from a single set-up position of the backhoe loader. In order to complete the assigned trench, after trenching to the extent of the reach of the backhoe, it becomes necessary to move the machine to a new set-up position so that excavating can continue and the trench can be completed. Often, it may be necessary to repeat this process several times where the proposed trench has a length several times the working extent of the machine performing the excavating operation.
The movement of a machine during a trenching operation, from one set-up position to another, may be referred to in a number of ways. For example, the movement may be referred to as a “hop,” or it may be referred to simply as a repositioning. Regardless of the name assigned to this movement to new set-up positions between excavating phases, the movement entails a number of particular acts and requires a significant measure of skill by the machine operator. For example, where the machine of choice for a trenching operation is a backhoe loader, the operator may be required to separately manipulate controls to alter engine speed, lift the loader bucket from ground engagement, retract machine stabilizers, alter engine speed again for engagement of a transmission gear, move the tractor or machine a proper distance for set-up, etc.
Since the excavating assemblage of a backhoe loader is mounted at the rear of the tractor, the operator is facing to the rear during an excavating phase, with the front of the tractor facing generally in the direction of the proposed (but not yet excavated) trench. For movement to a new set-up position, the operator must at some point reposition himself to face toward the front of the tractor, usually by swiveling the operator seat from a rear facing orientation to a front facing orientation. Controls for the backhoe, and perhaps the stabilizers, may be located convenient to the rear-facing direction, while controls for the loader bucket, steering, engine throttle, and brake may be located convenient to the front-facing direction.
Time may be lost in the individual performance by the operator of the several steps involved in machine movement. Swiveling between the rear facing and front facing positions to individually manipulate the several controls involved in movement to a new set-up position may be yet one more factor contributing to operator fatigue. Relying on the operator to determine the appropriate movement distance may not yield the most efficient repositioning of the tractor. It is desirable to maximize productivity by, for example, minimizing the number of machine repositionings, or hops, during an excavating operation by, for example, minimizing the repositioning or hop distance between excavating phases. Some efficient and effective manner of addressing these issues would be both beneficial and desirable.
U.S. Pat. No. 6,418,364 to Kalafut et al. relates to determining a position and heading of a work machine. The Kalafut et al. patent discloses that a machine, such as a backhoe loader, may be subject to shifting about from its initial position and heading during digging. Recognizing that a backhoe loader must frequently be moved as a trench is created, the Kalafut et al. patent discloses that, to compensate for such shifting, an external reference point is utilized to periodically assist in determining a new position and heading for the work machine. In this way, the machine apparently may be maintained on the planned trenching path.
While the arrangement in the Kalafut et al. patent may be useful for making machine corrections as a trenching operation progresses, the Kalafut et al. patent does not recognize the efficiency concerns associated with repositioning of the machine between excavating phases. Kalafut et al. does not disclose calculation and recommendation of an efficient permissible distance for machine movement during a repositioning phase between excavating phases. Thus, the system of the Kalafut et al. patent may not yield efficient repositioning of the machine between excavating phases in a multiple-phase excavating operation.
The disclosed embodiments are directed toward improvements and advancements over the foregoing technology.